IS 302-2-24 ( Superseding : 1994 IS 10542: 1983 ) ( Reaffirmed 2004 ) Indian Standard SAFETYOFHQUSEHOLDANDSIMILAR ELECTRICAL APPLIANCES PART Section 24 2 PARTICULAR REQUIREMENTS and Ice-Makers Refrigerators, Food-Freezers UDC 64.06-83 : 621.56592 : 614.825 Q BIS 1994 BUREAU MANAK OF BHAVAN, INDIAN STANDARDS ZAFAR MARG 9 BAHADUR SHAH NEW DELHI 110002 June 1994 Price Group 8 Electrical Appliances Sectional Committee, ET 32 FOREWORD This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Electrical Appliances Sectional Committee had been approved by the Electrotechnical Division Council. This standard covers general and safety requirements of refrigerators, food-freezers and ice-makers to ensure personal safety against electric shock, safety against the effects of excessive temperature and fire. This standard does not cover the performance requirement which are covered under separate Indian Standards. the This standard is to be read in conjunction with IS 302-l ( 1979 ). For the sake of covenience, clauses of this standard correspond to those of IS 302-l ( 1979 ). Clauses which are applicable ( which means that relevant provisions of the clauses apply ) or not applicable and necessary changes wherever required and indicated accordingly. Clauses/sub-clauses/tables which are additional to those of IS 302-l ( 1979 ) are numbered starting from 101; additional Annexes are lettered AA. Should, however, any deviation exist between IS 302-l ( 1979 ) and this standard, the provisions of the latter shall apply. While preparing this standard, assistance has been derived from IEC Pub 335-2-24 ( 1992 ) `Safety of household and similar electrical appliances: Part 2 Particular requirements for refrigerators, food food-freezers and ice-makers' issued by the Internafreezers and ice-maker, Section 24 Refrigerators, tional Electrotechnical Commission ( IEC ). This standard when published will supersede IS 10542 : 1983 LSpecification for safety requirements for refrigerator and food freezer for household and similar purposes', the requirements of which have been covered in this revised standard. The Indian Standards which are necessary adjuncts to this standard are given in Annex CC. For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test, shall be rounded off in accordance with IS 2 : 1960 `Rules for rounding off numerical values ( revised )`. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. IS 302-2-24 : 1994 hdian Standard SAFETYOFHOUSEHOLDANDSIMILAR ELECTRICAL PART Section 1 SCOPE 24 2 PARTICULAR Refrigerators, APPLIANCES REQUIREMENTS and Ice-Makers Food-Freezers This clause of IS 302-l except as follows. 1.1 Replacement ( 1979 ) is applicable such cases necessary. additional requirements may be This standard does not apply to: - This standard - applies to: - Appliances designed exclusively for industrial purposes; Appliances intended iocations where special such as the presence explosive atmosphere gas ); and Separate motors. to be used in conditions prevail, of a corrosive or ( dust, vapour or Electrical refrigerators with or without frozen food storage compartment, frozen food storage cabinets and food freezers and their combinations for household and similar use; Ice-makers incorporating a motor-compressor and ice-makers intended to be incorporated in food freezers or frozen food storage compartments; - - For appliances intended to be used in vehicles or on boardships or aircraft, additional requirements may be necessary. 2 TERMINOLOGY This clause of IS 302-l ( 1979 ) is applicable except as follows. 2.30 Addition Normal load for ice-maker - -. Refrigerators and freezers for camping use, touring caravans and for boats appliaThese for leisure purposes. nces may be mains operated, battery operated or operated either by mains or battery. They may also be in addition energized by another source ( gas or fuel ). It deals with safety for such appliances. It does not cover features of construction and operation of refrigerators and freezers which are covered under separate Indian Standards. Some tests related to stability and mechanical hazards are given in Annex BB. Where applicable, clauses of IS 302-l ( 1979 ) related to safety of heating applicance apply to absorption-type refrigerators or food feezers, and to heating elements incorporated in compression-type refrigerators or food freezers. Appliances not intended for normal household use, but which nevertheless may be a source of danger to the public, such as appliances intended to be used by laymen in shops, in light industry and on farms, are not within the scope of this standard. This standard does not take into account the specia.1 hazards which exist in nurseries and other places where there are young children or aged or infirm persons without supervision; in 1 when the ice-maker temperature of 22 & adjusted to their most setting can be altered Normal load for Load obtained is operated at the room 3°C and with any controls unfortunate setting if the by the user. incorporated ice-maker - Load obtained when the ice-maker is operated at the temperature of the frozen food storage compartment as prescribed by the relevant subclauses of this standard, with the supply water at a temperature of 22 f 2'C and with any control adjusted to their most unfavourable setting if the setting can be altered by the user. Additional Subclauses 2.101 Refrigerator Enclosed thermally insulated appliance of suitable volume and equipment for household use, cooled by a device consuming electric energy and having one or more compartment intended for the preservation of foodstuffs, one of them at least being maintained at a temperature above 0°C. IS 302-2-24: 1994 2.102 Frozen Food Storage Compartment Enclosed thermally insulated compartment of a refrigerator whose temperature is such that under the ambient reference conditions foodstuffs placed in it at a temperature of - 6"C, -12°C or - 18°C are maintained at this temperature or below. 2.103 Frozen Food Storage Cabinet insulated appliance or Enclosed thermally cabinet suitable for household use, cooled by means of a device consuming electric energy and whose one or more compartments having temperature is such that under ambient reference conditions foodstuffs placed therein, are mainequal to or temperature tained at a below - 18°C. 2.104 Food Freezer Enclosed thermally insulated appliance or cabinet of suitable volume and equipment for household use, cooled by means of a device consuming electric energy, and furnished with one or more compartments intended for the freezing of foodstuffs and suitable for the preservation of such foodstuffs at a temperature equal to or below - 18°C. 2.105 Compression-Type Appliance it is subsequently expelled at a higher partial vapour pressure by heating and liquefied by cooling in another heat exchanger ( condenser ). 2.110 Condenser Heat exchanger in which after compression vaporized refrigerant is liquefied by rejecting heat to an external cooling medium. 2.111 Evaporator Heat exchanger in which after pressure reduction, the liquid refrigerant is vaporized by absorbing heat from the medium to be refrigerated. 2.112 Free-Standing Appliance only. intended Appliance for open-type installation 2.113 Steady-State Considered to be obtained when three successive readings of the temperature, taken at approximately 60 min intervals, at the same point of any operating cycle, do not differ by more than 1°C. 3 GENERAL REQUIREMENTS The clause of 302-l ( 1979 ) is applicable. 4 GENERAL This NOTES ON TESTS Appliance in which refrigeration is effected by the vaporization at low pressure in a heat exchanger ( evaporator ) of a liquid refrigerant, the vapour thus formed being restored to the liquid state by mechanical compression to a in higher pressure and subsequent cooling another heat exchanger ( condenser ). 2.106 Ice-Maker Appliance in which ice is made by freezing water by a device consuming electric energy and having a compartment of storing the ice. 2.107 Incorporated Increment clause of IS 302-l except as follows. ( 1979 ) is applicable 4.2 Addition Tests on separate motor-compressors covered under a separate Indian Standard. 4.3 Replacement Tests of 11.7, 9,10,11.9 to 11.103 are carried out in this order after tests of 8. Before testing, the appliance at rated voltage for 24 h. 4.5 Addition Tests according to 9, 10, 11 and 12 out at an ambient temperature of on appliances of extended temperate temperate (N) temperature class or on appliances of subtropical ( ST (T) temperature class. Other tests are carried out temperature of ( 20 f 5 )"C. are carried ( 32 f l)OC ( SN ) and ( 43 f I)% ) or tropical ambient shall be operated are Ice-maker specially designed to be incorporated into food freezer or a frozen food storage compartment and without means for freezing water. 2.108 Ancillary Heating Element Heating device such as a defrost heater, door heater, anti-condensation heater, etc, which performs an auxiliary function. 2.109 Absorption-Type Appliance Appliance in which refrigeratl;loenafs effected by exchanger evaporation in a the ( evaporator ) of a liquid refrigerant, in the liquid state, the resulting vapour being then absorbed by an absorbent medium from which 2 at an Appliances rated for several climatic classes are tested at the ambient temperature relevant to the highest climatic class. IS 302-2-24 : 1994 4.6 Addition Tests are carried out with each source of energy ( electricity, gas or fuel ) in turn. Tests are additionally carried out with all combinations of sources supplied simultaneously unless this is prevented by interlocking devices. For the purpose of tests, the optional electric supply ( < 42 V ) is considered to be extra-low voltage supply. 4.7 Addition Appliances incorporating ice-makers are tested with the ice-maker operating to give the most unfavourable results. 4.13 Not Applicable Additional Subclause 4.101 Appliances which are so designed that an ice-maker may be incorporated in it are tested with the intended ice-makers. 5 RATING The clause of IS 302-I ( 1979 ) is applicable. 6 CLASSIFICATION The clause of IS 302-l except as follows. 6.1 Addition According to room temperature: temperature Appliances of extended class ( SN >; - Appliances of temperate class ( N ); - Appliances of subtropical class ( ST ); and - Appliances of tropical class ( T ). ( 1979 ) is applicable when a mixture is used, the individual name, numbers of chemical formulae. For compression-type refrigerating systems, the appliance shall also be marked with: - the mass of the refrigerant, or of each refrigerant in a mixture other than those of the azeotropic type. Moreover, appliances designed for incorporating an ice-maker shall be marked with the maximum input for an incorporated ice-maker, if greater than 100 W. Moreover, following: ice-makers shall be marked with the The maximum permissible water level, for appliances without automatic water-level control; - The maximum permissible inlet pressure, in pascals, bars or newtons per ems, for appliances intended to be connected to the water supply mains, unless this is indicated in the instruction sheet; and - The minimum permissible inlet water pressure in pascals, bars or newtons per cm2, if necessary for the correct operation of the ice-maker, unless this is indicated in the instruction sheet. Furthermore, appliances for camping or similar use shall be marked in addition with the source of supply other than electrical, if any. Moreover, the means provided for connection of the 12 V supply shall be clearly and permanently marked with the voltage and type of supply for which it is intended. 7.2 Not Applicable 7.12 Addition 7 MARKING This clause of IS 302-l except as follows. 7.1 Addition Moreover, appliances shall be marked with: ( 1979 ) is applicable For appliances designed for incorporating icemakers, the instruction sheet shall include the the type(s) of ice-maker(s) which can be incorporated. The instruction sheet shall also include an information on the fact that the installation of an ice-maker in an appliance must be made by the manufacturer's services. According to the type of ice-maker, the insulation shall also include the substance of one of the following warnings: Connected or to potable water supply only; - - The rated input of heating elements and auxiliary components if greater any than 100 W; The defrosing input, in watts, if greater than the input corresponding to the rated input; The letters SN, N, ST or T indicating the climatic class of the appliance; The rated maximum input of lamps, in watts; The chemical name or formula or the refrigerant number of the refrigerant or, 3 Fill with potable water only. Refrigerators and freezers for camping or similar use shall be accompanied with an instruction sheet including the details of the precaution to be taken for safe installation. IS 302-2-24 :1994 Moreover, the instruction sheet shall include in substance the indication for `camping use' and if appropriate, the indication of the fact that the appliance is provided with more than one separate supply. Moreover, the instruction sheet shall include a warning stating that the appliance shall not be used in open air and shall not expose to rain. 7.14 Addition In the case of free-standing appliances, the marking shall be visible, if necessary after moving the appliance away from the wall. The marking of the input of the lamp shall be while the lamp is being easily discernible replaced. 7.15 The use of the Standard Mark is governed by the provisions of Bureau of Indian Standards Act, 1986 and the Rules and Regulations made thereunder. The details of conditions under which the licence for the use of Standard Mark may be granted to manufacturers or producers may be obtained from the Bureau of Indian Standards. 8 PROTECTION SHOCK AGAINST ELECTRIC ( 1979 ) is applicable 9.1 Replacement Motors shall start under all normal conditions which may occur in use. Compliance is checked by the following voltage test: The appliance is started three times at 0.85 times the rated voltage at an ambient temperature of 32°C or 43°C according to its class ( see 4.5 ), the doors and lids being closed. The appliance is kept switched on after each start for a sufficient time to ensure that the motors start properly and that there is adequate lubrication. The interval between two successive starts shall be sufficiently long to prevent excessive over-heating of the motor, and to avoid an abnormal increase in the pressure of the liquid refrigerant, as well as to reach equalization of pressure between the high-pressure and low-pressure sides. Three chatterings of the starting relay of the motor-compressor are permitted. The supply source is such that the drop in voltage does not exceed 1 percent during the test. 9.2 Replacement Replace the test specifications by the following: after the table This clause of IS 302-l except as follows. 8.1 Addition Protecting covers of lamps, except those which do not need to be removed when replacing the bulb, are removed before applying the standard test finger. 8.2 and 8.3 Not applicable. 8.4 Addition For the purpose of the test, frozen regarded as a conducting liquid. 8.7 Not applicable. 9 STARTING OF MOTOR-OPERATED APPLIANCES This clause of IS 302-l except as follows. Addition after the Title Tine tests of this clause are carried. out at least 15 min after those of 11.7, but not later than 1 h after the latter. The test of 9.1 is not carried incorporating no other out on appliances motors than motor-compression complying with the locked motor test as specified in relevant Indian Standard on motor compressor and condenser fan motors complying with the locked rotor test cf Annex AA. 4 ( 1979 ) is applicable water is The wire has a silver content not less than 99.9 percent and is stretched horizontally along the centre line of a box with inside dimensions of 80 mm x 80 mm x 150 mm. The appliance is then started ten times at a voltage equal to 0.9 times rated voltage and ten times at a voltage equal to 1-I times rated voltage. The appliance is kept switched on after each start for a sufficient time to ensure that the motors start properly and there is adequate lubrication. The interval between two successive starts shall be sufficiently long to prevent excessive overheating of the motors and to avoid an abnormal increase in the pressure of the liquid refrigerant, as well as to reach equalization of pressure between the high-pressure and low-pressure sides. The chatterings of the starting relay motor-compressor are permitted. of the During the test, the ambient temperature is 32°C or 43°C according to the class of the appliance ( see 4.5 ), the doors and lids being closed. Heating elements incorporated in the appliance are operated, but are not connected to a separate supply. IS 302-2-24 : 1994 During the test, the silver wire shall not be melt and neither shall any overload protection device operate. 10 INPUT AND CURRENT This clause of IS 302-2 ( 1979 ) is applicable except as follows. 10.1 Replacement measured input of any auxiliary component shall not exceed the input marked on the appliance for these components by more than 20 percent, when such marking is given. Compliance is checked by measuring the input of auxiliary components when operated at rated voltage, when the input is stabilized. 11 TEMPERATURE RISE 10.102 The Replace the test specifications Compliance is checked input of the appliance conditions: by the following: by measuring the under the following This clause of IS 302-l ( 1979 ) is applicable except as follows. 11.2 Replacement Appliance for building-in are built in, dull black painted plywood walls, about 20 mm thick, being used. Free-standing appliances are placed in a test enclosure of plywood walls as specified above, the walls enclosing the appliance, as near to all its side and above as possible unless the manufacturer indicates in the instruction sheet that a free distance shall be observed from the walls or the ceiling, in which case this distance is observed during the test. Other appliances are placed in a test corner. The test corner consists of two walls at right angles, a floor and, if necessary, a ceiling as specified above. The appliance is placed in the test corner as follows: Appliances normally fixed to a wall are mounted on one of the walls, as near to the other wall and to floor or ceiling of the test corner as is likely to occur in normal use, unless the manufacturer has given other instructions concerning their installation. Appliances normally fixed to a ceiling are fixed to the ceiling of the test corner as near to the walls as is likely to occur in normal use, provided the manufacturer has not given special instructions concerning their installation. The appliance is placed in a room maintained at a temperature of 32°C or 43°C according to its class ( see 4.5 ) with the doors or lids open until the whole assembly is at room temperature. 11.4 Replacement Absorption-type appliances and heating elements, if any, are supplied at such,a voltage that the input is 1.15 times the maximum rated input. 11.5 Replacement The resistance of windings of compressor-type appliances is measured before the test when the appliance has reached room temperature. 5 For appliances other than those pre-set at the manufacturer's works, the thermostat is set to give the lowest temperature. The appliance is empty, with the doors and lids closed and the lamps, if any, switched Off. The tests are carried out at the rated voltage, the appliance being operated at an ambient temperature of 32°C or 43°C according to its class ( see 4.5 ). Ice-makers are operated under normal load. The result is measured when conditions are established. steady-state The measured input is the arithmetic mean value of the input between the making and the breaking of the thermostat, or between the highest and the lowest value measured respectively, excluding the starting input but including the input of the incorporated ice-maker, if any. 10.2 Replacement Replace the test specification by the following: given The test is made under the conditions in 10.1. The current is measured when conditions are established. steady-state The maximum value of the current measured between the making and breaking of the thermostat, excluding the starting current, is considered to be the current taken by the appliance. Additional Subclauses 10.101 The measured input of a defrosting system shall not exceed the rated defrost input marked on the appliance by more than 10 percent, when such marking is given. Compliance is checked by measuring the input of the defrosting system when the appliance operates on defrosting, at rated voltage. IS 302-2-24 : 1994 The appliance is supplied at the unfavourable voltage between 0.94 times the rated voltage and 1.06 times the rated voltage until steadystate has been reached. For this test, heating elements are supplied under the conditions indicated in 11.4. The measurement of the resistance of the windings is not made on motor-compressors complying with relevant Indian Standard. 11.6 Replacement In general, the supply conditions specified for absorption-type appliances apply also to motors incorporated in such appliances. In case of doubt, however, the conditions specified below apply. For combined appliances, when the motors are operated at a voltage equal to l-06 times the maximum rated voltage, the input to the heating elements is as specified in 11.4. When the motors are operated at a voltage equal to O-94 times the minimum rated voltage, the input to the heating elements is reduced to 0.90 times the minimum rated input. If it is necessary to make the test as an intermediate voltage, the input of the heating elements is adjusted proportionately. 11.7 Replacement Except for the tests of 11.10 to 11.103, the thermostat or similar control device is shortcircuited and doors or lids are closed. The appliance is then operated until steady-state conditions are established. Ice-makers and incorporated operated under normal load. Temperatures of the different appliance are then measured. 11.8 Keplacement Replace the following: text above the table by the ice-makers parts are For appliances of subtropical or tropical classes, the temperature rises are measured and shall not exceed the value given in the following table reduced by 1°C. Addition after the Table Moreover, the temperature of windings and the enclosure of the hermetic motor-compressors other than those complying with the Indian Standard are measured and shall not exceed the following values: Parts of the Appliance Temperature "C! Winding of the hermetic motor-compressors - Synthetic insulation - Cellulosic insulation or the like External enclosures of hermetic motor-compressors 11.10 Replacement 140 130 150 If the winding temperature of a hermetic motorcompressor other than those complying with relevant Indian Standard is higher than the temperature limit indicated in the table, the test is carried out again, the thermostat or similar control device being set at the lowest temperature, and the short-circuit of the device removed. The winding resistance of a running cycle, is measured at the end The corresponding temperature shall be not higher than the temperature limit indicated in the table. Additional Subclauses of the 11.101 Any defrosting assembly shall not give rise to temperatures likely to cause a fire or serious damage to the electrical insulation, combustible material, electro-valves or other electrical components. Compliance is checked by the following test During the test and before steady-state conditions are established the overload protection devices, if any, may operate. When steady-state conditions are established these devices shall not operate. During the test, sealing compound, if any, shall not flow out. For the test, the appliances are considered as liable to operate continuously for long periods. For the appliances of extended temperature or temperate classes, the temperature rises are measured and shall not exceed the value given in the following table. 6 The appliance is supplied at the most unfavourable voltage between O-94 and l-06 times the rated voltage: -- In the case of appliances where defrosting is manually controlled, until the evaporator is coated with a layer of ice of frost. A method of accumulation of frost for refrigerators only is given in 11.102. For other appliances, a method is under consideration. - In the case of appliances where defrosting is automatically or semi-automatically controlled, until the evaporator is coated IS 302-2-24 : 1994 with a layer of frost; however, this layer shall be not thicker than that which occurs, in normal use, during the intervals between the successive automatic defrosting operations, or, for the semi-automatic defrosting during the intervals between the defrosting operation recommended by the manufacturer. The defrosting assembly is then switched on by closing the circuit supplying the heating element or the valve, the supply voltage of the heating element being as defined in 11.4. When it is not possible to disconnect the heating element, the test is made with a supply voltage equal to 1.06 times the rated voltage for all the elements. If the defrosting time is controlled by an adjustable device, the device is set to the time given by the manufacturer. If a control device is used which stops the defrosting at a given evaporation temperature of pressure, the defrosting period is automatically terminated when the control operates. The temperatures of combustible materials and of electrical components liable to be affected by the defrosting operation are measured with thermocouples. The test.is continued until the minimum temperatures are reacted. The temperatures and temperature rises shall not exceed the values given in the table of 11.8. During the recovery period after defrosting, thermal overload protector may operate. the Provision shall be made ( for example, in the control of the supply of electrical energy to the device ) to ensure that the evaporation of water under normal conditions of use is capable of being maintained at a rate equal to: 2 g water/dma of cabinet gross volume/week. The electric energy to the device shall not be excessive but shall be sufficient to ensure the complete evaporation of the water. The amount of frost to be accumulated prior to the start of the defrosting test shall be based on this rate and on the time interval between two successive defrosts according to the manufacturer's instructions. For exampIe, if the manufacturer's instructions recommend defrosting twice weekly, then a refrigerator with a cabinet gross volume of 140 dms will require: 140 2gx-7= 140 g of water. The rate given above may be exceededin certain circumstances. The apparatus described ( see Fig. 1OlA and 1OlB ) has a maximum evaporating rate of approximately 2 g per hour when operating with an input of 4 W and with the water to be evaporated entering at cabinet temperature. Vision of the method of accumulation of frost is under consideration. 11.103 Ancillary heating element, other than defrosting assemblies incorporated in an appliance shall not give rise to excessive temperatures. Compliance is checked by the following test: Ancillary heating elements are energized, with the refrigerating device switched off if this is possible in normal use. They are supplied with a voltage as given in 11.4, until steady state conditions are reached. Temperature rises are measured by means of thermocouples fixed on the outside surface of the insulation of the ancillary heating element. Temperature rises shall not exceed the values specified in 11.8. 12 OPERATION UNDER OVERLOAD CONDITIONS OF APPLIANCES WITH HEATING ELEMENTS 12.1 This clause of IS 302-l ( 1979) is applicable except as follows. 12.1 Replacement Replace the test specifications by the following: For absorption-type appliances, compliance is checked by the tests of 12.2 carried out at an ambient temperature of 32°C or 43°C according to the class of the appliance ( see 4.5 ). 7 11.102 The accumulation of frost shall be produced by the use of a device having a controllable heat source directed on a measured amount of water for the purpose of evaporating this water over a predetermined period with a minimum of extraneous heat loss to the refrigerator cabinet. A convenient form of the apparatus would comprise a block enclosure of thermally insulating material having a vertical hole at its centre containing a light bulb mounted on a bottom plug directly below an operating dish with a high thermal conductivity base and low thermal conductivity walls ( see Fig. 1OlA and 1OlB ). The device described above should be mounted at the geometric centre of the refrigerator cabinet and the electrical connection brought conveniently to the outside so that the voltage applied may be varied and the power consumed measured with the refrigerator door in the closed position. Water is then introduced into the evaporating dish at the required rate through a length of small bore tube passing into the cabinet. A continuous flow is not necessary but the water should be injected at appropriate intervals. IS 302-2-24 : 1994 INSULATING I LTHERMAL FOAM INSULATING All dimensions in millimetres. FIG. 101 A WATER EVAPORATION FOR ACCUMULATION OF TB~T 15.1 Replacement Appliances shall be proof against splashing or spilling of liquids and humid conditions which may occur in normal use. Compliance is checked by the following tests: Ancillary heating elements are not tested since they are subjected to 19.101. 13 ELECTRICAL INSULATION AND LEAKAGE CURRENT AT OPERATING TEMPERATURE 13.1 Replacement Replace the test specifications by the following: Compliance is checked by the tests of 13.2 and, for absorption-type appliances and other heating elements by the additional test of 13.3, the appliance being operated under the conditions specified in 11.7. 14 RADIO AND TELEVISION INTERFERENCE SUPPRESSION This clause of IS 302-l ( 1979 ) is applicable. 15 MOISTURE RESISTANCE This Appliances other than ordinary are tested by the appropriate test of 15.2; Appliances subject to spillage of liquid in normal use are tested by the tests of 15.3; All appliances are tested by the tests of 15.4; Appliances subject to spilling of liquid inside are tested by the tests of 15.101; and to Appliances except those for building-in ice-makers by the tests of 15.102; and Ice-makers which are directly connected the water supply by the tests of 15.103. NOTE - If there is a possibility clause of 1s 302-l except as follows. ( 1979 ) is applicable that water deposit during a test could affect the results of the following test, the appliances is kept in normal test room atmosphere for 24 h before being subjected to the next test. 8 IS 302-2-24 : 1994 FIG. 101 B WATER EVAPORATION DEVICB FOR ACCUMULATION OF FROST After each of these tests, except 15.4, the appliance shall withstand the electric strength test specified in 16.4 and inspection shall show that water which may have entered the appliance, does not impair compliance with this standard; in particular, there shall be no trace of water on insulation which could result in the reduction of creepage distances and clearances below the limits specified in 29.1. 9 Immediately after the test of 15.4, the appliance shall withstand the tests of 16. 15.2 Addition ( beginning of the subclause ) The enclosure of drip proof, splash proof and watertight appliances shall provide the degree of protection against moisture in accordance with the classification of the appliance. IS 302-2-24 : 1994 15.3 Replacement The fourth paragraph of the test specifications: _., _._ . . . sub*Immediately after this treatment clause 29.1' is not applicable. 15.4 Replacement Replace the first two paragraphs specifications by the following: to the test the appliance being disconnected from the supply. The apparatus shown in Fig. 102 is filled with water to the level of the lip and the displacement block is supported just above the water by means of any suitable release mechanism and bridge support. The apparatus is supported with its base horizontal and so positioned and at such a height that the water is discharged over the part under consideration within the interior of the appliance and its front face in the most unfavourable manner when the release mechanism is operated. The test is made only once with the apparatusin any one position but the test may be repeated as many times as necessary in different positions provided that there is no residual water on parts wetted by a previous test. 15.102 Appliances other than those for buildingin only and other than ice-makers are tilted at an angle of up to 3' to the position of normal use in the direction which is likely to be the most unfavourable for this test, and half a litre of water containing approximately one percent NaCl is poured uniformly over the top of the appliance with the controls in the `on' position, Compliance is checked by the humidity treatment described in this subclause followed immediately by the tests of 16. The appliance is placed with its doors or lids open in the humidity cabinet and does not operate. Additional Subclauses 15.101 Appliances subject to spillage of liquid on the inside walls of the cabinet of compartment shall be so constructed that such spillage does not affect their electrical insulation. All shelves and containers which can be removed without the use of a tool are removed and the inside walls of the cabinet or compartment including any electrical components mounted thereon are subjected to the following tests, DISPLACEMENT BLOCK 7 RELEASE P,N, P 125 . =I are approximately All dimensions in millimetres. The displacement block has a volume of 140 f 5 ml and a mass of 200 f 10 g, dimensions 112 x 50 x 25. The dimensions of the vessel are inside dimensions and the tolerance is + 2. FIG. 102 APPARATUSFOR SPILLAGE TBST 10 IS 302-2-24 : 1994 the appliance being disconnected from the supply * 15.103 For ice-makers which are directly connected to the water supply, the container and\ or that part of the appliance which serves as container IS filled with water as in normal use and the inlet valve is left open until spillage occurs and additional for a further minute. Where no spilling occurs owing to the fact that advice prevents such spillage, the inlet valve is rendered in operative for a further 5 min following the operation of this device. 16 INSULATION RESISTANCE AND ELECTRIC STRENGTH ( After the Humidity Treatment ) This clause of IS 302-l except as follows. 16.3 Addition Add the following item in the Table: For appliances for camping or similar use. Between circuits supplied at extra-low voltage and the mains supply 16.4 Addition Add the.following item in the Table: Class III Appliawes Class II Appliawes Other Appliantes c!impressor, only once for a given type of motor-compressor in the conditions stated in relevant Indian Standard, unless the motor-compressor has been previously tested and complies with the relevant Indian Standard; -_ For - absorption-type tests of 12; appliances, by the for appliances provided Furthermore, with a condenser fan motor, by the test of 19.6 and the locked-rotor test carried out on a separate motor, only once for a given type of fan motor under the conditions stated in Annex AA; Temperatures of motor windings other than condenser fan motors are not measured; temperatures of Wmding pressors are not measured; motor-com- - ( 1979 ) is applicable, - for appliances provided Furthermore, with other motors, by the test of 19.6; Furthermore, for ice-makers, of 19.102; and by the test 7 M - Furthermore, for appliances for camping or similar use, by the test of 19.103. 19.2 to 19.5 Not applicable. 19.7 Replacement Appliances incorporating three-phase motors, except three-phase motor-compressors complying with relevant Indian Standard, are operated under normal load, with one phase disconnected for a period as specified in 19.6. Further details of this test ration. 19.8 Not applicable. 19.9 Replacement Illuminating equipment shall not cause any life hazard under abnormal operating conditions. Compliance is checked by the following tests: The complete illuminating equipment including its protective cover, fitting with a lamp as recommended by the manufacturer, is operated for 12 h at l-06 times rated voltage. The refrigerator unit is switched off, the appliance is empty and doors or lids are fully opened. If the lamp does not attain the rated maximum input at rated voltage, the voltage is varied until the rated/input is reached and then increased to 10.6 times this voltage. During the 11 test, no development of smoke are under conside- For appliances for camping simtlar use bztn ween circuits supported at extralow voltage and the main supply - 3 750 V 3 750 V 17 OVERLOAD PROTECTlON This clause of IS 302-l ( 1979 ) is applicable. 18 ENDURANCE This clause of IS 302-l ( 1979 ) is not applicable. 19 ABNORMAL OPERATION This clause of IS 302-l ( 1979 ) is applicable except as follows. 19.1 Replacement Appliances shall be so designed that the risk of fire, mechanical damage related to safety of electric stock as a result of abnormal or careless operation is obviated as far as is practicable. Compliance is checked: - For compressor-type test carried out applications, on a separate by the motor- IS 302-2-24: 1994 shall appear and surrounding plastic parts shall not show any distortion which may affect in the sense of this standard. After the test, protection against electric shock shall be in compliance with 8 and the electric strength test according to 16 shall be withstood, the test voltage being applied only between current-carrying parts and accessible metal parts. 19.11 Addition The temperature of the enclosure of motorcompressors other than those which have been tested separately according to the relevant Indian Standard, is determined at the end of the test period or at the instant of operation of fuses, thermal cut-outs, motor protection devices and the like, and shall not exceed 150°C. Addition& 19.101 Subclauses at the upper limit of the rated voltage range. Only one fault condition is reproduced at a time, the tests being made consecutively. During the tests, the ice-maker or the appliance incorporating an ice-maker shall not emit flames or motion metal and the temperature of windings shall not exceed the values shown in the table of 19.6. After the test, the appliance the requirements of 19.11. Examples of fault conditions - shall comply with are: Timber stopping in any position; Disconnection and reconnection of one or more phases of the supply during any part of the programme; Open-circuiting components; or short-circuiting valve; and of - Ancillary heating elements shal! be so dimensioned and located that there is no risk of fire even in the case of abnormal operation. Compliance is checked following test: by inspection and the Failure of magnetic Operation with an empty container. to those give the cases most Ancillary heating elements are operated cdntinuously at a voltage equal to l-1 times rated voltage of the appliance, under steady conditions are established. If there is more ihan one ancillary heating element, they are operated each in turn, unless failure of a single component will cause two or more to operate together in which case they are tested in combination. If such a heating element is intended to be switched on and off by the use, it is operated together with the above combination. If a thermal cut-out operates or if the currer.t is otherwise interested, for example, due to the rupture of an intentionally weak are part before steady-state conditions established, the heating period is considered to be terminated. During this test, there shall be no emission of this smoke, flames or molten metal. The refrigerating unit is not switched off if this prevents the heating element to operate. 19.102 Ice-makers shall be so designed that the risk of life, mechanical hazard or electric shock is obviated as far as it is practicable in the event of incorrect operation of the development of defects in control devices or in their associated devices. Compliance is checked by applying any defect which may be expected in normal use, while the ice-maker and incorporated ice-maker is operated under normal load and at rated voltage or In general, tests are limited which may be expected to unfavourable results. The tests of this subclause are made with the tap closed or opened whichever gives the most unfavourable results. For the purpose of these tests, thermal are not short-circuited. controls Components complying with the relevant Indian Standard are not open-circuited or short-circuited, provided the appropriate standard covers the conditions which occur in the appliance. Water level switches complying with IEC 1058 are not short-circuited during these tests. The test during which the automatic device is held open has already been during the test of 15.3. filling made 19.103 For appliances intended for camping or similar use compliance is checked by operating the appliances at an ambient temperature of 32°C or 43°C according to the class of the apphance. The appliance is placed on a support inclined in the most unfavourable position by 5" and is operated at rated voltage or rated data of other source of energy respectively until steady-state conditions are established. During the test, non-self-resisting thermal cutouts which are only accessible with the aid of a tool or which require the replacement of a part shall not operate and no vapour of ignitable gas shall accumulate in the appliance. 12 IS 302-2-24 : 1994 20 STABILITY HAZARDS AND MECHANICAL ( 1979 ) is applicable to ice-makers 22.11 Addition Thermostats, with the exception of their thermo-sensitive basis, shall not be arranged inside the evaporator unless they are adequately protected against condensation on cold surface and against the effect of water formed during the defrosting process. Compliance is checked by inspection as storms and tube of thermostat. 22.15 Not applicable. 22.26 and 22.29 Not applicable. Additional 22.101 21.101 Subclause This clause of IS 302-l except as follows. 20.1 This subclause is applicable only. Moreover for refrigerators of Annex BB applies. 21 MECHANICAL and freezers, the test part such STRENGTH This clause of IS 302-l ( 1979 ) is applicable except as follows. Additional Subclause Appliances for camping or similar use, other than fixed appliances and appliances for building in shall withstand the following tests: Lamps shall be effectively protected against mechanical shocks either by devices placed on their support or by the supports themselves. Lampholders shall be so fixed that they do not work loose in normal use. Normal use includes replacement of the bulb. Compliance is checked by inspection and, if necessary, by a test subjecting the lampholders to a torque of 0.15 Nm for El4 and B15 lampholders, and 0.25 Nm for E27 and B22 lampholders The lampholders shall then withstand a pull test with 50 N, applied for 1 min in the direction of the axis of the lampholders. 22.102 Mains-operated heating conducts ( defrost heaters,. door heaters, butter heaters, etc ) and their joints, located in the refrigerator/freezer compartments or in the thermal insulation shall be watertight. Compliance is checked by immersing three samples of the complete heating conductor in water containing approximately I percent NaCl and having a temperature of ( 27 f 5 )"C for a period of 24 h. A voltage of2 000 V is then applied for 15 min between the heating conductor(s) and the water. During the test, no breakdown shall occur. The appliance is placed on a horizontal wooden panel which is dropped 50 times from a height of 5 cm onto a solid base or wood. The appliance is then fastened in its normal position of use to the vibration-generator by the encloure. The means of straps round direction of vibration is vertical, and the severity is: Duration Amplitude Sweep frequency Sweep rate range 30 min O-35 mm ti II;, 55 Hz, Approximately one octave per minute After the tests, the appliance shall show no damage affecting the safety; in particular, no connection or part the loosening of which might impair safety shall have loosened. 22 CONSTRUCTION This clause of IS 302-l except as follows. 22.1 Replacement Appliances shall not be of Class 0 or Class 01. Compliance is checked by inspection relevant test. 22.3 Modification Replace the test specification by the following: and by the ( 1979 ) is applicable In the meaning of the paragraph, connections to electrical terminals are not joints. 22.103 Ice-makers and appliances incorporating ice-maker shall withstand the water pressure to which may be subjected in normal use. Compliance is checked by subjecting those parts of the ice-makers and appliances incorporating ice-maker which are under pressure from the water supply mains, for 5 min to a static pressure equal to twice the maximum permissible inter water pressure or 1.2 MPa = 12 bar = 120 N/cmt, whichever is the greater. 13 Compliance is checked by verifying that the appliance operations without dangers in all positions from the normal position of use by an angle not exceeding 2". 22.8 and 22.9 Not applicable. IS 302-Z-24 : 1994 During the test, there shall be no leakage any part including the inter water hose. 23 INTERNAL WIRING from - A set of supply leads for permanent connection to fixed wiring; An appliance inlet; and A power supply cord. This clause of IS 302-l ( 1979 ) is applictble. 24 COMPONENTS This clause of IS 302-l except as follows. 24.1 Addition For stating capacitors, the voltage across the capacitors shall not exceed 1.3 times the rated voltage of the capacitor when the appliance is operating at 1*I times the rated voltage. Motor-compressors are not required to be separately tested according to relevant Indian Standard nor as they required to meet all requirements of relevant Tndian Standards if they meet all requirements of the appropriate appliance standard. 24.3 Addition Voltage selection switches used in appliances for similar use shall disconnect all poles and shall have a contact separation of at least 3 min. 24.4 Not applicable. 24.5 Replacement Socket-outlets inside Class 1 appliances are permitted; they shall be provided with an earth-contact. Compliance is checked by inspection manual test. 24.6 Addition Lampholders Compliance shall be of the insulated type. is checked by inspection. and by a ( 1979 ) is applicable Appliances shall not be provided with more than one means of connection to the supply, with the exception that appliances consisting of two or more completely indented unit; built together in one casing may be provided with more than one set of terminals or with more than one power supply cord. Addition Appliances for camping or similar use intended for optional connection to the mains supply and to a 12 V supply shall be equipped with a mains supply cord and a supply cord or separate terminals for the connection of the 12 V supply. 25.3 Addition It shall not be possible to remove the connector from the appliance by a pull on the flexible cord before an independent operation to release the locking means has been carried out. 25.6 Replacement The light polyvinyl chloride sheathed flexible cord complying with IS 694 : 1977 is also allowed for appliances having a mass exceeding 3 kg. Addition For rated currents up to 3 A, a nominal crosssectional area of 0.5 mm2 is allowed provided the length of the cord does not exceed 2 m. The length of the cord is measured between the point where the cord, or cord guard enters the appliance or connector, and the entry to the plug. 26 TERMINALS CONDUCTORS FOR EXTERNAL 24.9 Not applicable. 25 SUPPLY CONNECTION AND EXTERNAL FLEXIBLE CABLES AND CORD This clause of TS 302-l except as foll0wS. ( 1979 ) is applicable This clause of IS 302-I ( 1979 ) is applicable, except for parts related to motor-compressors, if the motor-compressor complies with relevant Indian Standard. 27 PROVISION OF EARTHING This clause of IS 302-l ( 1979 ) is not applicable complying with the to motor-compressors relevant Indian Standard. 25.1 Replacement Replace the requirement by the following: with one of the to the supply: connecAppliances shall be provided following means of connection - This clause of IS 302-l ( 1979 ) is applicable, except for part related to motor-compressors if the motor-compressor complies with relevant Indian Standard. 28 SCREWS AND CONNECTIONS This clause of IS 302-I ( 1979 ) is applicable, except for parts related to motor-compressors if the motor-compressor complies with relevant Indian Standard. 14 A set of terminals for permanent tion to fixed wiring; IS 302-2-24 : 1994 29 CREEPAGE DISTANCES, CLEARANCES AND DISTANCES THROUGH INSULATION Table 101 Schedule of Type Tests ( Clause 101.1 ) Clause Protection shock against electric This clause of IS 302-l ( 1979 ) is applicable, except for parts related to motor-compressors if the motor-compressor complies _ with IEC 335-2-34. 29.1 Addition Add to the table the following: In appliance for camping or similar use: `between deperated circuits for optional operation with extra-low voltage and main supply' I +1qv3/+_I-_I 30 RESISTANCE TRACKING Sl No. Reference 8 9 10 i) ii) iii) Starting of motor operated appliances Input Temperature rise iv) v) vi) 11 12 13 Operation under overload conditions Electrical insulation and leakage current at operating temperature Radio and television interference suppression Moisture resistance TO HEAT, FIRE AND vii) viii) ix) 14 15 16 This class of IS 302-I ( 1979 ) is applicable, except for parts related to motor-compressors if the motor-compressor complies with relevant Indian Standard. 30.1 Addition Accessible parts of non-metallic material within the storage compartment are regarded as external parts. For accessible parts of non-metallic material within the storage compartment, the temperature value of ( 75 & 2 )"C is replaced by ( 65 f 2 )"C. 31 RESISTANCE TO RUSTING Insulation resistance and electric strength ( after humidity treatment ) Overload Endurance Abnorma! operation mechanical protection x) xi) xii) xiii) xiv) xv) xvi) xvii) xviii) 17 18 19 20 21 22 23 24 and cab!es external 25 Stability and hazards Mechanical Construction Internal wiring strength Components Supply connection external flexible and cords Terminals conductors Provision for This clause of IS 302-l ( 1979) is applicable, except for parts related to motor-compressors if the motor-compressor complies with the relevant Indian Standard. 32 RADIATION, HAZARDS TOXICITY AND SIMILAR xix) xx) 26 27 28 for earthing This clause applicable. 101 TESTS of IS 302-l ( 1979 ) is not xxi) xxii) xxiii) xxiv) xxv) Screws and connections Creepage distance clearances Resistance tracking Resistance Radiation and 29 30 31 32 to heat, fire and to rusting hazards 101.1 Type Test The tests specified in Table 101 shall constitute the type tests and shall be carried out on two samples 01 the same type and ratmg selected preferably at random from a regular production lot. Before commencement of the tests, the samples shall be visually examined and inspected for obvious visual defects in respect of components, parts of their assembly, construction, mechanical hazards, markings, provision of suitable terminals for supply connections, earthing and the effectiveness iof screws and connections. The external surface finish shall be even and free from finishing defects. 15 101.1.1 Criteria of Acceptance Both samples shall successfully pass all the type tests for proving conformity with the requirements of the standard. If any of the samples fails in any of the type tests, the testing authority at its discretion, may call for fresh samples not exceeding twice the original number and subject them again to all tests or to the test(s) in which failure(s) had occurred. No failure should be permitted in the repeat test(s). IS 302-2-24 : 1994 101.2 AcceptanceTests The following tests: shall Test a) Protection 8) Provision the acceptance NOTE - for earthing 27 constitute For the purpose of acceptance tests, the humidity treatment shall be done for 24 hours the test for moisture resistance Clause Reference against 8 10 11 13 while conducting ( 15 1. electric shock b) Input c) Temperature rise d) Electrical insulation and leakage current at operating temperature e) Moisture resistance f) Insulation resistance and electric strength ( after humidity treatment ) 101.2.1 A recommended sampling procedure for acceptance tests is given in Appendix B of IS 302-I ( 1979 ). 101.3 Routine The following Test shall constitute Test the routine tests: Clause Reference 8 13.3.2 of IS 302-I ( 1979 ) 27 15 16 a) Protection against electric shock b) High voltage c) Provision for earthing ANNEX A TABLESOFTYPETESTS Appendix A of IS 302-l ( 1979 ) is not applicable. ANNEX B SAMPLING PROCEDURE FOR ACCEPTANCE TESTS Appendix B of IS 302-l ( 1979 ) is not applicable. ANNEX C ELECTRONIC CIRCUITS circuits are used. Appendix C of IS 302-I ( 1979 ) is applicable if electronic ANNEX MEASUREMENT Appendix D of IS 302-l D OF TEMPERATURE WITH THERMOMETER ( 1979 ) is applicable. ANNEX E ALTERNATIVE TESTS FOR PROTECTED MOTOR UNITS Appendix E of IS 302-l ( 1979 ) is not motors. applicable to motor-compressors and to condenser fan 16 IS 302-2-24: 1994 ANNEX F IMPACTTESTSAPPARATUS Appendix F of IS 302-l ( 1979 ) is applicable. ANNEX THERMAL CONTROLS G AND OVERLOAD RELEASES if thermal controls and overload releases are used. Appendix G of IS 302-l ( 1979 ) is applicable ANNEX MEASUREMENT OF CREEPAGE H AND CLEARANCES DISTANCES Appendix H of IS 302-l ( 1979 ) is applicable. ANNEX J PROPERTIES TESTS FOR FIRE RESISTING Appendix .I of IS 302-l ( 1979 ) is applicable. ANNEX K OF COPPER BNF JET TEST FOR DETERMINATION OF THICKNESS AND NICKEL PLATING Appendix K of IS 302-l ( 1979 ) is not applicable. ANNEX APPROXIMATE L ON MEASUREMENT OF THICKNESS OF CHROMIUM NICKEL, STEEL AND COPPER Appendix L of IS 302-l ( 1979 ) is not applicable. ANNEX AA ( Clause 9 ) LOCKED-ROTOR TEST OF CONDENSER FAN MOTORS The enclosure and winding of a condenser fan motor shall not reach excessive temperatures if the motor locks or fails to start. Compliance is checked by the following test: The fan and its motor are mounted on wood or similar material. The motor's rotor is locked. Fan blades and motor brackets are not removed. The motor is supplied at rated voltage; the supply circuit is given in Fig. AAl. 17 The assembly is to operate under these conditions for 15 days ( 360 h ), unless the protective device, if any, permanently opencircuits by failure period to the expiration of that time. In this case, the test is discontinued. If the temperature of motor windings stays lower than 9O"C, the test is discontinued when steady-state conditions are reached. Temperatures are measured under conditions stated in 11.3. IS 302-2-24 : 1994 During the test, enclosure and winding temperatures shall not exceed the values stated in 19.6. The polarity every 24 h. of the supply shall be inverted Seventy-two hours after the beginning of the test, the motor shall withstand an electric strength test as specified m 16.4. An earth-leakage circuit-breaker is connected so as to disconnect the supply in the event of an earth current of more than 30 mA. ) s = Supply M = Fan motor P = Protection device ( external or internal F = Leakage circuit breaker 30 mA FIG. AA1 SUPPLY CIRCUIT FOR LOCKED-ROTOR TEST OF CONDENSER FAN MOTOR At the end of the test, the leakage current is measured between windings and the body at a voltage equal to twice the rated voltage; its value shall not exceed 2 mA. ANNEX BB ( Clauses 1.1 and 20.1 ) STABILITY AND MECHANICAL HAZARDS Appliances including ice-makers intended to be used on a surface such as a floor or a table shall have adequate stability. Compliance is checked by the following tests: The empty appliance is disconnected from the supply and placed on a horizontal support and the door is opened through an angle of approximately 90°C. Cylindrical weights, having a diameter of 80 mm and a mass of 0.5 kg, are placed on each of the door shelves starting as far as possible from the hinge and touching each other all along the shelf, except for a space less than 8 cm wide at the end of the shelf. Two of these weights are placed in each position on these shelves where a milk bottle can be accommodated, whereas one weight only is placed on all other shelves, excepting those which are specifically designed for storing eggs only. A weight having a mass of 2-3 kg is then placed on top of the door, 4 cm from the edge furthest from the hinge, the door being opened through an angle of approximately 90". This test is repeated with the door opened through an angle of approximately 180" or to the limit of the door-stop, whichever results in the smaller angle. During these tilt. tests, the appliance shall not 18 For appliances provided with more than one door, the tests are made on each door separately. It is not necessary for the weights to lie flat on the shelves. If the shelf is too narrow, the weights may either overhang or be tipped up, but there shall be no more than one weight, or two weights for milk bottles, for each 8 cm length of the shelf. If egg racks can be removed, the relevant shelf is not considered to be specifically designed for storing eggs only. Damage to, and deformation of, doors, hinges and shelves are neglected. In the case of appliances with a volume of 60 litres or more, and for reasons of safety, the door, if it is not locked, should be capable of being opened from the inside. In addition, the force required door shall not exceed 70 N. Compliance for opening the is checked by the following test: The door shall be maintained closed for a period of 1 h after which an `opening test' shall be carried out under the following condition: The force of opening shall be applied to the handle at the point farthest from the hinges, in a direction perpendicular to the plane of the door, by means of a spring balance. IS 302-2-24 : 1994 ANNEX CC ( Foreword ) The following Indian Standards adjuncts to this standard: IS No. 302-l ( 1979 ) Title are necessary IS No. 694 : 1990 Title revision ) PVC insulated cables for working voltages up to and including 1 100 volts ( third insulated cables: working voltages and including (first revision ) Safety of household and similar electrical appliances: Part 1 General requirements (fifth revision ) 9968 ( Part 1 ) : 1988 Elastomer Part 1 For up to 1 100 volts 19 Brueau of Indian Standards BIS is a statutory institution established under the Bureau harmonious development of the activities of standardization, and attending to connected matters in the country. Copyright BIS has the copyrlght of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. This does not preclude the free use, in the course of necessary details, such as symbols and sizes, type or grade of implementing the standard, designations. Enquiries relating to copyright be addressed to the Director ( Publications ), BlS. Review of Indian Standards Amendments are issued to standards as the need arises on the basis of comments. Standards are also reviewed periodically; a standard along with amendments 1s reaffirmed when such review indicates that if the review indicates that changes are needed, it is taken up for revision. no changes are needed; Users of Indian Standards should ascertain that they are in possession of the latest amendments or edition. This Indian Standard has been developed from Dot : No. ET 32 ( 3691 1. of Indian Standards Act, 1986 to promote marking and qualit!, certification of goods Amendments Amend No. Issued Since Publication Date of Issue Text Affected BUREAU Headquarters: Manak Bhavan, 9 Bahadur Shah Zafar Telephones : 331 01 31, 331 13 75 Regional Central Eastern Northern Southern Western Offices : : Manak Bhavan, 9 Bahadur NEW DELHI 110002 : l/14 C. I. T. Scheme CALCUTTA 700054 : SC0 445-446, Sector OF INDIAN STANDARDS Marg, New Delhi 110002 Telegrams : Manaksanstha ( Common to all offices ) Telephone Shah Zafar Marg Maniktola 160036 600113 331 01 31 { 331 13 75 37 84 99, I 37 86 26, 53 38 43, t 53 23 84 37 85 61 37 86 62 53 16 40 VII M, V. I. P. Road, 35-C, CHANDIGARH MADRAS : C. I. T. Campus, : Manakalaya, BOMBAY IV Cross Road, Marol, 235 02 16, 235 04 42 I 235 15 19, 235 23 15 632 92 95, 632 78 91, 632 78 58 632 78 92 E9 MIDC, 400093 Andheri ( East ) Branches BANGALORE. BHOPAL. : AHMADABAD. BHUBANESHWAR. COIMBATORE. FARIDABAD. GHAZIABAD. GUWAHATI. HYDERABAD. JAIPUR. KANPUR. LUCKNOW. PATNA. THIRUVANANTHAPURAM. Printed at New India Plinting Pri%8. I